UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                -----------------

                                    FORM 8-K


                                 CURRENT REPORT
                     Pursuant to Section 13 or 15(d) of the
                         Securities Exchange Act of 1934

         Date of Report (Date of earliest event reported): July 21, 2006


                                ICOS CORPORATION
             (Exact name of registrant as specified in its charter)

         Washington                      0-19171                 91-1463450
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(State or other jurisdiction of        (Commission            (I.R.S. Employer
 incorporation or organization)        File Number)          Identification No.)


                   22021 - 20th Avenue S.E., Bothell, WA 98021
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               (Address of principal executive offices) (Zip code)


                                 (425) 485-1900
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              (Registrant's telephone number, including area code)


                                 Not Applicable
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              (Former name, former address and former fiscal year,
                          if changed since last report)

Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions:

|_| Written communications pursuant to Rule 425 under the Securities Act (17 CFR
230.425)

|_| Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR
240.14a-12)

|_| Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange
Act (17 CFR 240.14d-2(b))

|_| Pre-commencement communications pursuant to Rule 13e4(c) under the Exchange
Act (17 CFR 240.13e-4(c))



ITEM 2.02. Results of Operations and Financial Condition

     On July 21, 2006, Lilly ICOS LLC, our 50/50 joint venture with Eli Lilly
and Company, which is marketing Cialis(R) (tadalafil) for the treatment of
erectile dysfunction, issued a press release announcing its financial results
for the quarter ended June 30, 2006. A copy of the press release is furnished as
Exhibit 99 to this report and is incorporated herein by reference.


                                    SIGNATURE


     Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.

                                                   ICOS CORPORATION


Date: July  21, 2006                               By: /S/ MICHAEL A. STEIN
      --------------                                   -------------------------
                                                       Michael A. Stein
                                                       Senior Vice President and
                                                       Chief Financial Officer




                                  EXHIBIT INDEX

Exhibit No.   Description

99            Press Release of Lilly ICOS LLC dated July 21, 2006, reporting
              Lilly ICOS' financial results for the quarter ended June 30, 2006.